To be honest, I don't think that the HP or the last CT should be changed this drastically, but I would like to see at least enough health to survive one AWP headshot (maybe 500?).
For the !lr option, !rebel, you gain a large amount of health based on CTs alive, and it is meant to put you on the same level and provide a high percentage of winning the round by killing all remaining CTs, I don't think this should be the case for the last CT, you are usually given the situation of fighting many unarmed Prisoners, many of which are often hiding. Because of this, I think it would be fine for last CT health to remain about the same, maybe a slight increase to 500.
(Also I'll take this time to address a small issue, if you were the original warden and did not lose the extra health you get when you get last CT, if you !pass, you lose your last CT health and your bonus warden health, !pass > 425 hp to 100 hp, not usually a common or big issue)